This update is a standalone update that is targeted for Windows 10, version 1703 (Creators Update). This update also includes Intel microcode updates that were already released for these operating systems at the time of release to manufacturing (RTM). We will offer additional microcode updates from Intel through this article for these operating systems as they become available to Microsoft. By default, this mitigation is turned off for Spectre Variant 4 (CVE-2018-3639: "Speculative Store Bypass (SSB)"). Please make sure that mitigation against Spectre Variant 4 (CVE-2018-3639: "Speculative Store Bypass (SSB)") is enabled for Windows client through the registry settings that are documented in the following article: